The present invention relates generally to pet food technologies. More specifically, the present invention relates product cooling apparatuses and methods of using same.
There are a number of conventional coolers for cooling extruded pet food products. For example, a typical cooler has a cooling compartment that receives bulk pet food to be cooled. There are usually a number of pivotable bars or slats below an outlet at the bottom of the compartment for collecting the pet food. The mechanical bars or slats are designed to allow the passage of cooling air through and around the pet food accumulated on the slats. The slats can be rotated in one position to form a floor collecting the pet food for cooling and another position to allow the passage of the pet food into a collection hopper. The cooling capability of this type of cooler is limited relative to it's total volume due to the fact that by the nature of it's design, an empty collection hopper must be provided below the slats in order to collect cooled product, and this space provides no cooling function. Further, the slats tend to collect a residual of fine product material that remains even when the slats are rotated, which can lead to contamination problems. The mechanical slats also require a substantial effort and safety precautions to clean between production runs and as the moving parts are pneumatically or hydraulically driven through linkages, maintenance can be costly.
Another cooler design set forth in U.S. Pat. No. 5,906,482 for cooling extruded feed products includes a cooling chamber with an outer wall surrounding the inner chamber. This forms a cooling air circulating chamber right outside the inner cooling chamber. Apertures are formed in a wall between the air circulating chamber and the cooling chamber thereby allowing cooling air to flow into the cooling chamber through the apertures. Air flow exits near the top as pet food product is dropped from a product inlet in the top of the cooling chamber. The product exits at the bottom of the cooling chamber. Nevertheless, there are a number of problems that arise from this design. First, small pet food products such as pellets and fines or coating materials (e.g. fats) thereof may plug the apertures thereby reducing the efficiency of the cooling process. Sanitation issues also arise with particulates from the pet food falling through the apertures and remaining in the exterior air circulating chamber. Further, since the cooling air apertures extend up the side wall of the cooling chamber, not all cooling air contacts all material in the cooling chamber, limiting cooling efficiency.
Therefore, there is a need to provide improved coolers that allow for flexibility in design for alternate capacities and rates for cooling pet food products.